What are the possible reasons lying behind DVT?

A DVT is a blood clot in one of the veins in the leg, which stops blood flow back to the heart.
It can occur for several different reasons such as:

Immobility due to surgery

Accident

A long flight or journey

A family history of DVT

Contraceptive pills and hormone replacement therapy (HRT)

Medical and genetic conditions

Pregnancy

What are the factors that increase the risk of developing DVT?

Obesity

Smoking

Over 40 years of age (particularly if you have a condition that restricts your mobility)

What are the Symptoms of DVT?

Symptoms in the leg include:

Swelling

Pain

Warm skin

Tenderness

Redness( particularly at the back of your leg and below the knee)

What is the reliable diagnostic tool for DVT?

Diagnosis of a DVT is normally made by a scan of the veins in your leg; referred to as a 'Duplex' scan.

A DVT usually (although not always) affects one leg. The pain may be made worse by bending your foot upward towards your knee. In some cases, there may be no signs or symptoms of DVT at all in the leg. The problem may only become apparent when a pulmonary embolism (blood clot formation inside veins of the lung) develops as a result of the blood clot in the leg. Symptoms of a pulmonary embolism include breathlessness, chest pain, and in severe cases collapse. Both DVT and pulmonary embolism are serious conditions that require urgent investigation and treatment.

Treatment

Treating Deep Venous Thrombosis (DVT) will prevent the clot getting larger, breaking off, (an embolism), and travelling up the vein to your lungs. It can also reduce the risk of post-thrombotic syndrome and prevent a further DVT from occurring in the future.
The usual treatment regimen will include: